WARNING: The following contains spoilers for Marauders #8 by Gerry Duggan, Stefano Caselli, Edgar Delgado, VC's Cory Petit and Tom Muller, on sale now.
Sebastian Shaw is building something right under the X-Men's collective nose. As the Black King of the Hellfire Trading Company, Shaw is one of the most powerful leaders in the mutant nation Krakoa. He's already made his son, Shinobi Shaw, the Black Bishop of the Hellfire Trading Company, and he also just eliminated his chief political rival on Krakoa by drowning Kitty Pryde.
And in Marauders #8, Sebastian Shaw adds another two dangerous Marvel villains to his growing cabal. This issue reveals that Shaw has recruited Andreas and Andrea von Strucker, the mutant siblings who are better known as Fenris, to be his new Black Knights.
Created by Chris Claremont and John Romita, Jr., the twins first appeared in Uncanny X-Men #194. As the children of key Hydra figurehead Baron von Strucker, their mutant powers were genetically modified in utero as they were being experimented on by Arnim Zola. When these twins hold hands, the siblings each have the ability to fire various types of energy blasts.
Shortly after they debuted, they tried to assassinate Magneto during his trial before the World Court in Uncanny X-Men #200. Although they initially only wanted to kill Magneto for his apparent role his their father's supposed death, the X-Men's efforts to prevent the assassination put them firmly in the duo's crosshairs going forward.
After floating around the Marvel Universe for a few years, Fenris joined the Upstarts, a group of mutants who engage in a mutant-hunting competition overseen by the Gamesmaster. Although they failed to bring Omega Red into the fold or kill Wolfsbane, they were both accepted onto the short-lived team, where they operated alongside Shinobi Shaw.
A few years later, Andrea was killed by Baron Zemo, who was posing as the heroic Citizen V in the Thunderbolts. On Zemo's orders, Andreas was brainwashed by the Purple Man to become the new Swordsman. In one particularly gruesome detail, Zemo has Purple Man make Andreas skin his sister’s body and wrap the handle of his sword with it so that he can continue to use their combined powers.
Eventually, Andreas breaks free of Purple Man’s brainwashing and joins the Thunderbolts, where he retains the Swordsman identity. He stays through the change over to Norman Osborn’s leadership and the superhero Civil War, where he participates in the dysfunctional group's infighting.
After he learns that Arnim Zola cloned Andrea, he gives his cloned sister a piece of his flesh so that she can use their shared abilities on her own too. However, this clone is killed by Bullseye during Secret Invasion, a death that the other Thunderbolts credit to the Skrulls. During a subsequent confrontation with Osborn, the former Green Goblin killed Swordsman too.
In 2015, both siblings mysteriously returned and operated Club Fenris, a nightspot for supervillains. Although the credit their revival to their father, they may have been early test subjects for what evolved into Krakoa's resurrection protocols.
Regardless of how they came back, they obviously took up Charles Xavier's offer to let mutant villains live peacefully on Krakoa. With these two filling out the leadership of the Black arm of the Hellfire Company, that group looks like the most villainous team on Krakoa. The Shaws and the von Struckers are all mutants who put their own personal gains and needs over those of mutantkind, and there's no telling how much trouble they can cause if they're all working together.